bullets containing combustible pellets to produce smoke or light along the trajectory of a projectile. Allows shooter to trace the flight of the bullets.

Ammunition containing a chemical composition to mark the flight of projectiles by a trail of smoke or fire.

A radioactive element whose pathway through which a chemical reaction can be followed. (Basic Science/Radiography/usesradioactivity.htm)(Course Material/Radiography/Physics/carbondating.htm)

A radioactive substance use to study biological processes. Radioactivity

A radioisotope introduced into a system as a tracking signal, the movement of which can be followed to trace the movement of parts of that system.

Trains Two fund separation theorem